1. Field of the Invention
The present invention relates to a drug container suitable for aseptically mixing a drug contained therein with a solvent or a diluent contained in another container and to a dual container system for fluid therapy employing the same.
2. Description of the Prior Art
In medical facilities such as hospitals, some drugs are mixed with a solvent or diluent just before use to prepare a parenteral fluid for intravenous drip infusion. Such drugs are generally supplied in the form of powder or a freeze-dried preparation and packaged in a drug container or a vial because of their poor conservation stability in the liquid state or of any other reasons. It is therefore required to mix the drug in the container or vial with a solvent or diluent contained in another container. In this case, the drug container or vial is usually connected to the solvent container by a suitable connecting means such as, for example, a double ended needle or a connecting tube to transfer the solvent or diluent to the drug container. However, such procedures are very troublesome and time-consuming. In addition, there is a fear of contamination of the drug as it is required to make a hole in a stopper of the drug container in air to connect it with the solvent container.
To solve such problems, there have been proposed various drug delivery systems. For example JP-T-S61-501129, corresponding to U.S. Pat. No. 4,583,971, discloses a closed drug delivery system comprising a flexible container having a liquid diluent therein, a capsule coupled to the flexible container, a drug vial having a drug therein and being supported in the capsule, and a means for coupling the capsule to the interior of the flexible container. In this system, the drug vial is communicated with the flexible container through a communicating means arranged in the coupling means, thus making it possible to aseptically mix the drug with the solvent.
U.S. Pat. No. 4,936,841 (corresponding to JP-A-H2-1277) discloses a container system comprising a flexible container containing a diluent, a capsule having a cylindrical connecting portion at its one end and being connected to a mouth portion of the flexible container at the connecting portion, a drug container held in the capsule, and a communicating means arranged in the capsule to form a passage communicating the flexible container with the drug container. In this system, the communicating means is firstly pierced into the drug vial and then pierced into the flexible container to communicate the flexible container with the drug container. Since the flexible container is communicated with the drug container in the closed system, it is possible to aseptically mix the drug with the solvent.
JP-A-H3-37067 discloses a container for infusion fluid comprising a bag member of a thermoplastic resin, a drug vial held in the bag member at the inverted state, a liquid container containing a diluent, a flexible cylindrical member connected to the bag member at one end and to the liquid container at the other end, a communicating means arranged between the drug container and the liquid container and housed in the cylindrical member, and a means for supporting the drug container and the liquid container, said supporting means being positioned between the drug vial and the liquid container so as to prevent the two containers from coming close to each other until aseptic communicating and mixing operations have been completed.
However, it is impossible with these three systems to change the combination of the drug and solvent or diluent as the drug vial is paired with the liquid container.
JP-A-S59-209535, corresponding to U.S. patent Ser. No. 470,105 filed Feb. 28, 1983 and Ser. No. 565,126 filed Dec. 23, 1983, discloses a drug delivery system comprising a first flexible container having an opening at one end, and a second container having a removable stopper and capable of being fixed to the bottom wall of the first container therethrough, and a stopper removing means having a portion engaging with the stopper. JP-B- H2-26506, corresponding to U.S. patent Ser. No. 590,601 filed Mar. 19, 1984, discloses an improved drug delivery system having a structure similar to that of JP-A-S59-209535. Also, JP-A-S62-137056 (corresponding to U.S. Ser. No. 806,782 filed Dec. 9, 1985) and H2-4375 (corresponding to U.S. Ser. No. 138,810 filed Dec. 28, 1987) discloses an improved drug container for use in the drug delivery system of JP-A-S59-209535. These drug delivery systems make it possible to perform substantially aseptic operations as well as to optionally select the combination of a drug with a solvent or diluent as occasion demands.
However, these drug delivery systems are complex in structure and may give an unpleasant feeling to a patient as the stopper of the drug container is dropped into the liquid container.